Ford 6.7 Powerstroke Engine Oil
API CK-4 Spec, Viscosity & Drain Intervals for the 6.7 Power Stroke Diesel
The Ford 6.7 Power Stroke requires API CK-4 oil. Ford specifies WSS-M2C171-F1 for the 6.7 diesel. Primary viscosity: 10W-30 (Ford’s preferred grade for fuel economy) or 15W-40. FA-4 is not approved. Ford does not publish a proprietary spec beyond WSS-M2C171-F1 — any CK-4 oil meeting that standard qualifies. AMSOIL Signature Series Max-Duty 15W-40 (DME) and Heavy-Duty 15W-40 (ADP) both meet CK-4 requirements.
Displacement
6.7L
Horsepower
250–500 hp
Torque
440–1,200 lb-ft
Oil Capacity
~13 qt / 14.2 qt
OEM Spec
WSS-M2C171-F1 / CK-4
Primary Grade
10W-30 or 15W-40
Generation Overview
The 6.7 Power Stroke has been in production since 2011 across three generations:
- Gen 1 (2011–2014): Original platform, 400 hp max
- Gen 2 (2015–2019): Revised turbo, 450 hp max
- Gen 3 (2020+): Compacted graphite iron block, 500 hp max
All generations use the same base oil specification — CK-4, WSS-M2C171-F1.
Ford’s Viscosity Preference
Ford specifies 10W-30 as the preferred grade for the 6.7 Power Stroke for fuel economy optimization. 15W-40 is also approved. Both are CK-4 — the HTHS floor is identical (≥3.5 mPa·s). In cold climates, 10W-30 provides better cold-start protection without sacrificing hot-film strength.
Oil Capacity by Application
| Application | Capacity |
|---|---|
| F-250/350/450 (standard) | 13.0 qt |
| F-450/550 Super Duty | 12.3 qt |
| F-650/750 | 14.2 qt |
Always verify your exact capacity via dipstick after fill — 6.7 Powerstroke sump capacity varies by chassis configuration. Pre-fill the filter before installation.
Common 6.7 Powerstroke Oil Issues
- EGT (exhaust gas temperature) spikes under load accelerate oxidation — full synthetic handles this better than conventional
- High-mileage 6.7s (300K+) may show increased oil consumption — monitor level between changes
- Delete trucks (EGR/DPF removed): still run CK-4, no SAPS restriction applies without aftertreatment
If your 6.7 Powerstroke has had EGR/DPF delete: CK-4 is still the correct specification. Low-SAPS chemistry is harmless without aftertreatment. High-SAPS conventional oil is also acceptable on deleted trucks.
Drain Intervals
- Stock truck with OEM aftertreatment: 7,500–10,000 miles (Ford OEM recommendation) or per oil life monitor
- Extended drain with full synthetic: 10,000–15,000 miles with monitoring
- Fleet/commercial applications: Follow Ford’s fleet service guidance
Recommended AMSOIL Products
Signature Series Max-Duty
AMSOIL DME — 15W-40
Full synthetic CK-4. Maximum protection under extreme EGT and load conditions. Meets WSS-M2C171-F1.
Heavy-Duty Diesel
AMSOIL ADP — 15W-40
Full synthetic CK-4. Cost-effective performance for standard drain intervals. Meets WSS-M2C171-F1.
Frequently Asked Questions
What oil does the Ford 6.7 Powerstroke take?
API CK-4 meeting Ford WSS-M2C171-F1. Primary grade: 10W-30 (Ford preferred) or 15W-40. FA-4 is not approved for the 6.7 Power Stroke.
How often should I change oil on a 6.7 Powerstroke?
Ford recommends 7,500–10,000 miles or per the oil life monitor for stock trucks. With full synthetic CK-4, extending to 10,000–15,000 miles is reasonable with oil level monitoring.
Is 5W-40 OK in a 6.7 Powerstroke?
Not Ford’s primary recommendation. Ford specifies 10W-30 or 15W-40. 5W-40 may be acceptable in cold climates — verify your specific model year’s service documentation before deviating from the OEM spec.
What’s the oil capacity of the Ford 6.7 Powerstroke?
Varies by chassis: F-250/350 is approximately 13 quarts with filter. F-450/550 is 12.3 quarts. F-650/750 is 14.2 quarts. Always verify via dipstick after fill.